We had a similar thing happen some years ago. My wife went out to the pen, went into it, and then saw dead chickens all around. Then two dogs came out of the chicken house and started growling at her and coming toward her. She ran out and slammed the gate to keep them from getting her. I think they could have jumped over the fence to get out, just as they had done to get in, but they didn't. She came in and told me about it. I went out with my shotgun and killed both of them. The owner was mad and threated to sue me for killing his VALUABLE dogs. I told him he was lucky his dogs didn't get my wife. Then I told him to call the animal control office or the sheriff's dept and tell them about it. I knew they would tell him that he had a responsibility to keep his dogs home and that I had a right to defend my family and animals. I never heard any more from him.